动态自适应流媒体技术的研究与实现

发布时间：2018-05-09 21:56

本文选题：流媒体 + 自适应流媒体　；参考：《中国科学院研究生院（沈阳计算技术研究所）》2014年硕士论文

【摘要】：近年来人们的生活品质不断提高，对于高质量的视频和音频内容的需求也越来越强烈。网络设施的不断完善，为高质量视频音频的传递提供了基础。随着智能手机和平板电脑的爆发式兴起，人们的上网方式也改变了许多。尤其是3G甚至4G网络的投入使用，为人们提供了更便捷的观看流媒体内容的方式，从而进一步提高了流媒体服务在人们生活中的重要性。在这种情况下，传统的流媒体技术已经无法满足人们的需求，基于HTTP的动态自适应流媒体技术成为了研究人员和流媒体服务商的新选择。然而，目前对于码率选择算法尚没有一致的评价标准，国内成熟的DASH解决方案也比较少，因此对于基于HTTP的动态自适应流媒体技术的研究非常有必要。本文首先分析了基于HTTP的动态自适应流媒体技术特点和MPEG-DASH标准，深入研究了与该技术相关联的各方面的内容，包括媒体传输方式、视频和音频编解码器、封装格式等技术。然后从基于HTTP的动态自适应码率选择算法入手，在研究已有码率选择算法的基础上，通过分析客户端运行环境的特点，结合码率选择算法的目标，设计了一种基于缓冲区等级的码率选择算法。在此基础上，设计并实现了一个基于HTTP的动态自适应流媒体系统，对其中的内容准备、客户端实现和网络模拟等技术进行了更深入的分析和研究。最后设计了多种网络场景在该系统上对码率选择算法进行了实验分析，实验结果表明，本文提出的码率选择算法在带宽利用和保持视频质量的平滑等方面有很好的效果。
[Abstract]:In recent years, the quality of life has been improved, and the demand for high-quality video and audio content has become more and more intense. The continuous improvement of network facilities provides the basis for the transmission of high-quality video and audio. With the explosion of smartphones and tablets, the way people surf the Internet has changed a lot. Especially the use of 3G and 4G networks provides people with a more convenient way to watch streaming media content, thus further improving the importance of streaming media services in people's lives. In this case, the traditional streaming media technology has been unable to meet the needs of people, the dynamic adaptive streaming media technology based on HTTP has become a new choice for researchers and streaming media service providers. However, there is no consistent evaluation standard for rate selection algorithms and there are few mature DASH solutions in China, so it is necessary to study the dynamic adaptive streaming media technology based on HTTP. In this paper, the characteristics of dynamic adaptive streaming media technology based on HTTP and the MPEG-DASH standard are analyzed, and the contents of this technology are deeply studied, including media transmission mode, video and audio codec, encapsulation format and so on. Then start with the dynamic adaptive rate selection algorithm based on HTTP, on the basis of studying the existing rate selection algorithm, through analyzing the characteristics of the running environment of the client, combining the target of the rate selection algorithm, A rate selection algorithm based on buffer level is designed. On this basis, a dynamic adaptive streaming media system based on HTTP is designed and implemented. Finally, a variety of network scenarios are designed to carry out experimental analysis on the rate selection algorithm. The experimental results show that the proposed rate selection algorithm has a good effect on bandwidth utilization and maintaining smooth video quality.
【学位授予单位】：中国科学院研究生院（沈阳计算技术研究所）
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN919.8

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